Heated fluid distribution apparatus for combined domestic hot water supply and space heating system

ABSTRACT

A combined domestic hot water supply and space heating system includes a single water heating system, one or more space heating systems and a heated fluid distribution apparatus. The apparatus has piping that provides communication between the apparatus, the water heating system, the space heating system, a fresh water source, and a house tap. The apparatus also includes anti-scalding device, a temperature and pressure gauge that monitors hot water temperature, a priority device that controls flows between the pipes and other safety and maintenance devices.

BACKGROUND OF THE INVENTION

The present invention is related to a system that provides both domestichot water and space heating. More particularly, the invention is relatedto an apparatus that properly distributes heated water from a singewater heating system to domestic hot water and space heatingapplications.

Most building or houses that require a domestic hot water supply as wellas space heating use separate appliances for each purpose. For example,a conventional tank type gas water heater or an electric water heaterhas been used for domestic hot water supply. Conventional tank type gasheater or electric heater has disadvantage that it takes significantamount of space and it continuously lose heat energy due to its stand.

Conventionally, when space heating is required, a separate furnace orany hydronic space heater has been used. The furnace or heater has itsown gas burner or electric heating element. This scheme is inefficientand waste space and energy.

A more compact and efficient hot water and space heating system has longbeen in need.

SUMMARY OF THE INVENTION

An objective of the present invention is to provide a compact andefficient combined domestic hot water supply and space heating system.

Another objective of the invention is to provide a fast, safe andreliable combined domestic hot water supply and space heating system.

In order to achieve the above objectives, the present invention providesa combined domestic hot water supply and space heating system thatincludes a water heating system, a space heating system and a heatedfluid distribution apparatus.

The heated fluid distribution apparatus includes a cold water inletfitting that is adapted to be connected to a fresh water source, a hotwater outlet fitting that is adapted to be connected to a house plumbingfixture, a water outlet fitting that communicates with an inlet of thewater heating system, a water inlet fitting that communicates with anoutlet of the water heating system, a space inlet fitting thatcommunicates with a space heating system return fitting of the spaceheating system, and a space outlet fitting that communicates with aspace heating system inlet fitting of the space heating system.

The water heating system may be an on demand flow through tankless waterheater, or a fully modulating device, which can supply hot water at apredetermined temperature ranging from about 100° F. to about 180° F.

The apparatus further includes an anti-scalding valve, whichcommunicates with the cold water inlet fitting and the water inletfitting and has an outlet that is connected to the hot water outletfitting. The temperature of water from the anti-scalding valve is set toabout 120° F.

The apparatus further includes a temperature and pressure gauge thatindicates incoming hot water temperature from the outlet of the waterheating system.

The apparatus further includes two three-way valves that change thecombined domestic hot water supply and space heating system into abypass mode in which the combined domestic hot water supply and spaceheating system is operated for providing domestic hot water to the houseplumbing fixture.

The apparatus further includes a priority device and a control board forprioritizing domestic hot water. The priority device is connected to thecontrol board. The control board controls activation and deactivation ofthe three way valves. The control board is adapted to communicate with ahouse room thermostat for turning on/off of the space heating system.

The apparatus further includes an expansion tank and an air separatorbetween the water inlet fitting and the cold water inlet fitting. Theexpansion tank and the air separator balance pressure and automaticallyeliminate air in water flows between the water inlet fitting and thecold water inlet fitting.

The apparatus further includes a thermostatic mixing valve, whichcommunicates with the water inlet fitting and the space inlet fitting,and includes an outlet that is connected to the space outlet fitting.

The apparatus further includes a circulation pump between the spaceinlet fitting and the water outlet fitting. The circulation pumpprovides water head that is high enough to activate a flow sensor forthe water heating system. The circulation pump includes a check valvethat prevents backflow from the water outlet fitting to the space outletfitting.

The apparatus further includes a space check valve that prevents coldwater backflow to the space heating system, and a water check valve thatprevents return water backflow to the cold water inlet fitting.

The present invention utilizes an on-demand water heater, which is smallenough to hang on a wall, as a water heating system. Sine the waterheater has no reservoir tank, the water heater takes significantly lessspace compared to conventional water heater. Fully modulating computercontrolled gas valve brings out significant energy saving. Automaticflow adjustment valve supplies hot water at desired temperature. Varioussizes of input water heating system can be used anywhere.

The present invention wisely controls conjunction of hot water supplyand space heating with flow through type water heating system and spaceheating. Combining domestic hot water and space heating system involvesa lot of confusion and difficulties in practice especially incontrolling heat generation system, heated water temperature and flowrate.

The present invention supplies and maintains potable domestic hot waterat steady temperature, maximizes efficiency in output BTU in supplyinghot water, and maximizes efficiency in space heating by optimizedcontrol for radiant floor heating system, base board heating system, orforce air heating system with a single flow through water heatingsystem. The single flow through water heating system adopts an on-demandtankless water heater or an instantaneous water heater.

The present invention utilizes an open loop system and a semi-closedloop system simultaneously. The open loop system is used for domestichot water supply, and the semi-closed loop system is used for spaceheating mostly.

The present invention may be applied for various space heating systemand wide area applications. For flow through water heating system thatoffers between 110,000 BTU/hour to 350,000 BTU/hour, the presentinvention can continuously produce hot water from 2 GPM to 12 GPM with77° F. rise from ground water temperature. The present invention usesthis hot water effectively to the combination of domestic hot watersupply and space heating.

The distribution apparatus is used for distributing heated water topotable domestic hot water supply and space heating with the singlewater heating system.

The apparatus includes the priority device for supplying domestic hotwater at 120° F., the step down mixing valve, the circulation pump forspace heating, and safety and performance devices.

The single water heating system is a flow through type, and has theinlet for replenishing the system with unheated water and the outlet forsupplying heated water. The water heating system can be set to providehot water at 100° F.˜180° F. depending on the space heating system.

The space heating system includes a radiant in floor space heating, baseboard space heating and forced fan assistant space heating system. Thetemperature drop through the space heating system is designed to 14°F.˜35° F. on average using predetermined water flow rate and hot watertemperature.

Although the present invention is briefly summarized, the fullerunderstanding of the invention can be obtained by the followingdrawings, detailed description and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with reference to theaccompanying drawings, wherein:

FIGS. 1 a and 1 b are perspective views of a heated fluid distributionapparatus for a combined hot water supply and space heating systemaccording to the present invention;

FIG. 2 is a schematic diagram showing the heated fluid distributionapparatus; FIG. 3 is a schematic diagram showing the combined hot watersupply and space heating system;

FIG. 4 is a schematic diagram showing a water heating system; and

FIGS. 5 a and 5 b are schematic diagrams showing space heating devices.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 a and 1 b show a heated water distributing apparatus 32according to the present invention. FIG. 2 shows that the apparatus 32has a cold water inlet fitting 21 for connection to a filtered andtreated water source (not shown) as a potable fresh water source. Theapparatus 32 also has a hot water outlet fitting 23 that deliversdomestic hot water at a predetermined temperature, which is set about120° F. The domestic hot water outlet fitting 23 normally supplies thehousehold potable hot water via potable hot water taps or any plumbingfixtures that use potable hot water.

FIG. 3 shows that the apparatus 32 has a water inlet fitting 24 that isconnected to an outlet 2 of a water heating system 31. The apparatus 32has a water outlet fitting 22 that is connected to an inlet 1 of thewater heating system 31 for replenishing unheated water. The waterheating system 31 is an on demand flow through tankless water heater,and uses gas (Natural gas or Propane gas) or electricity. Alternatively,the water heating system 31 is a fully modulating device, which cansupply hot water at a predetermined temperature ranging from about 100°F. to about 180° F.

The cold water inlet fitting 21, the water inlet fitting 24, the wateroutlet fitting 22, the hot water outlet fitting 23 of the apparatus 32,and the inlet 1 and the outlet 2 of the water heating system 31 are madeof ¾″ copper pipe and fittings.

The apparatus 32 has a space outlet fitting 20 that is connected to aspace heating system inlet fitting 27 or 29 as a heated water supplyfitting, and a space inlet fitting 19 that is connected to a spaceheating return fitting 28 or 30 as a return conduit for reheating water.The space inlet fitting 19 and the space outlet fitting 20 of theapparatus are made of 1″ copper pipe.

Referring to FIG. 2, the apparatus 32 has an anti-scalding device 9 forsetting domestic hot water supply at 120° F. The anti-scalding device 9is connected to the inlet fitting 24 and the cold water inlet fitting21, and it has an outlet that is connected to the hot water outletfitting 23.

The apparatus 32 has a priority device 8 for prioritizing domestic hotwater. The priority device 8 is connected to the control board 26. Thecontrol board 26 controls activation and deactivation of three wayvalves 11, 15.

The apparatus 32 has a temperature and pressure gauge 7 that indicatesincoming hot water temperature from the outlet 2 of the water heatingsystem 31. The temperature is between 100° F.˜180° F. depending on thetemperature set in the water heating system 31. The temperature andpressure gauge 7 is used to prevent high temperature replenish water.

The apparatus 32 has an air separator 10, an expansion tank 13 and apressure regulator 12 for adjusting heated water pressure in spaceheating systems 33, 34 (refer to FIG. 3).

The apparatus 32 has a thermostatic mixing valve 17, which has an inletthat is connected to the water inlet fitting 24, and another inlet thatis connected to the space inlet fitting 19, and an outlet that isconnected to the space outlet fitting 20 for supplying tempered hotwater to the space heating system. As explained above, the space inletfitting 19 is connected to the space heating return fitting 28 of thespace heating system 33 or the space heating return fitting 30 of thespace heating system 34. The space outlet fitting 20 is connected to thespace heating system inlet fitting 27 of the space heating system 33 orto the space heating system inlet fitting 29 of the space heating system34. The thermostatic mixing valve 17 keeps preset heated water supplytemperature around 110° F. for the radiant space heating system 33 andabove 140° F. for the forced air space heating system 34.

The apparatus 32 has a circulation pump 16 between the space inletfitting 19 and the water outlet fitting 22 for circulating heated waterin closed loop at the space heating system 33 or 34.

When temperature drops between the space outlet fitting 20 and the spaceinlet fitting 19 around 14° F.˜35° F. from the supply temperaturedepends on the space heating system 33, 34.

The circulation pump 16 provides water head that is high enough toactivate a flow sensor 54 for the water heating system 31. Thecirculation pump 16 includes a check valve 56 that prevents backflowfrom the water outlet fitting 22 to the space outlet fitting 20.

The apparatus further includes a space check valve 58 that prevents coldwater backflow to the space heating system 33, 34, and a water checkvalve 14 that prevents return water backflow to the cold water inletfitting 21.

A house space heating thermostat 44 is connected to the control board 26of the apparatus 32 for activating a space heating mode. When the spaceheating thermostat 44 is engaged to start, the control board 26 startsthe circulation pump 16, which circulates heated water through the spaceheating circuit. The temperature of circulated water is set around 110°F. for a radiant floor heating system, around 180° F. for a base boardheating system. The heated water supply temperature is set above 140° F.for a forced air space heating system.

The domestic hot water capacity is from 2 GPM to 10 GPM depending on theinput rate of the water heating system 31.

The operation of the invention is explained. If there is a request fordomestic hot water supply through the domestic hot water outlet fitting23, fresh cold water is supplied through the cold water inlet fitting21. Immediately after the cold water supply, the priority device 8communicates to the control board 26, and the control board 26 controlsthe three way valves 11, 15 to change to a bypass mode in which thewhole system is operated for providing domestic hot water to householdplumbing fixtures.

If there is no request for domestic hot water supply, and a thermostatfor house space heating sends request for heating, the whole system isoperated only for space heating with semi-closed loop system untildomestic hot water supply is requested.

The room air temperature in the bypass mode may drop 2° F.˜10° F. fromthe room air temperature before the bypass mode is activated in about 20minutes. The temperature drop depends on the heat insulation rate of thehouse.

The apparatus 32 of the present invention with the single water heatingsystem 31 and the space heating systems 33, 34 can satisfy most ofdomestic hot water requirements for traditional household plumbingfixtures. The relationship between the input capacity and hot water flowrate is explained under the predetermined temperature of 120° F. for theanti-scalding device 9.

Basic Equation for apparatus 32 that produces hot water as is, and incase that the hot water temperature of the water heating system 31 isset above 120° F.Input BTU×Efficiency (%)=500×GPM×ΔT

-   -   Where    -   Input BTU by BTU/hour    -   ΔT=preset temperature−fresh cold water temperature    -   GPM as gallons per minute

Actual GPM with 120° F. can be predicted with the following equation:GH=(TM−TC)/(TH−TM)

-   -   Where    -   GH: Gallon of hot water requirement for one gallon of cold water    -   TM: Cold and hot water mixture temperature (The apparatus is set        as TM=120° F.)    -   TC: Fresh cold water temperature    -   TH: Output hot water temperature in the water heating system

The input BTU may be changed depending on each house's domestic hotwater requirement and/or space heating requirement.

While the invention has been shown and described with reference todifferent embodiments thereof, it will be appreciated by those skilledin the art that variations in form, detail, compositions and operationmay be made without departing from the spirit and scope of the inventionas defined by the accompanying claims.

1. A heated fluid distribution apparatus for a combined domestic hotwater supply and space heating system, wherein the combined domestic hotwater supply and space heating system comprises a water heating systemand a space heating system, the apparatus comprising: a) a cold waterinlet fitting that is adapted to be connected to a fresh water source;b) a hot water outlet fitting that is adapted to be connected to a houseplumbing fixture; c) a water outlet fitting that is adapted tocommunicate with an inlet of the water heating system; d) a water inletfitting that is adapted to communicate with an outlet of the waterheating system; e) a space inlet fitting that is adapted to communicatewith a,space heating system return fitting of the space heating system;and f) a space outlet fitting that is adapted to communicate with aspace heating system inlet fitting of the space heating system;
 2. Theapparatus of claim 1, further comprising an anti-scalding valve, whereinthe anti-scalding valve communicates with the cold water inlet fittingand the water inlet fitting and has an outlet that is connected to thehot water outlet fitting.
 3. The apparatus of claim 2, wherein thetemperature of water from the anti-scalding valve is set to about 120°F.
 4. The apparatus of claim 1, further comprising a temperature andpressure gauge that indicates incoming hot water temperature from theoutlet of the water heating system.
 5. The apparatus of claim 1, furthercomprising two three-way valves that changes the combined domestic hotwater supply and space heating system into a bypass mode in which thecombined domestic hot water supply and space heating system is operatedfor providing domestic hot water to the house plumbing fixture.
 6. Theapparatus of claim 5, further comprising a priority device and a controlboard for prioritizing domestic hot water, wherein the priority deviceis connected to the control board, wherein the control board controlsactivation and deactivation of the three way valves.
 7. The apparatus ofclaim 6, wherein the control board is adapted to communicate with ahouse room thermostat for turning on/off of the space heating system. 8.The apparatus of claim 6, further comprising an anti-scalding valve,wherein the anti-scalding valve communicates with the cold water inletfitting and the water inlet fitting and has an outlet that is connectedto the hot water outlet fitting.
 9. The apparatus of claim 8, furthercomprising an expansion tank and an air separator between the waterinlet fitting and the cold water inlet fitting, wherein the expansiontank and the air separator balance pressure and automatically eliminateair in water flows between the water inlet fitting and the cold waterinlet fitting.
 10. The apparatus of claim 9, further comprising athermostatic mixing valve, which communicates with the water inletfitting and the space inlet fitting, and comprises an outlet that isconnected to the space outlet fitting.
 11. The apparatus of claim 10,further comprising a circulation pump between the space inlet fittingand the water outlet fitting.
 12. The apparatus of claim 1, furthercomprising an expansion tank and an air separator between the waterinlet fitting and the cold water inlet fitting, wherein the expansiontank and the air separator balance pressure and automatically eliminateair in water flows between the water inlet fitting and the cold waterinlet fitting.
 13. The apparatus of claim 1, further comprising athermostatic mixing valve, which communicates with the water inletfitting and the space inlet fitting, and comprises an outlet that isconnected to the space outlet fitting.
 14. The apparatus of claim 1,further comprising a circulation pump between the space inlet fittingand the water outlet fitting.
 15. The apparatus of claim 14, wherein thecirculation pump provides water head that is high enough to activate aflow sensor for the water heating system.
 16. The apparatus of claim 15,wherein the circulation pump comprises a check valve that preventsbackflow from the water outlet fitting to the space outlet fitting. 17.The apparatus of claim 1, further comprising a space check valve thatprevents cold water backflow to the space heating system.
 18. Theapparatus of claim 1, further comprising a water check valve thatprevents return water backflow to the cold water inlet fitting.
 19. Acombined domestic hot water supply and space heating system comprising:a) a water heating system; b) a space heating system; and c) a heatedfluid distribution apparatus; wherein the heated fluid distributionapparatus comprises: 1) a cold water inlet fitting that is adapted to beconnected to a fresh water source; 2) a hot water outlet fitting that isadapted to be connected to a house plumbing fixture; 3) a water outletfitting that communicates with an inlet of the water heating system; 4)a water inlet fitting that communicates with an outlet of the waterheating system; 5) a space inlet fitting that communicates with a spaceheating system return fitting of the space heating system; and 6) aspace outlet fitting that communicates with a space heating system inletfitting of the space heating system.
 20. The system of claim 19, whereinthe water heating system is an on demand flow through tankless waterheater.
 21. The system of claim 19, wherein the water heating system isa fully modulating device, which can supply hot water at a predeterminedtemperature ranging from about 100° F. to about 180° F.